A METHOD FOR GEAR SELECTION DURING DRIVING OF A VEHICLE IN A HEAVY UPHILL DRIVE CONDITION

摘要

A method for gear selection during driving of a vehicle in a heavy uphill drive condition, said vehicle comprising an engine (1), an automated mechanical transmission (9), a clutch (3), a control unit (45) for receiving input signals including signals indicative of vehicle speed, engaged ratio of said transmission, rotational speed of said engine, rotational speed of a input shaft and displacement of a throttle control (48) for engine torque request, and for processing said signals in accordance with programmed logic rules to issue command output signals to said engine (1), to said transmission (9) and to said clutch (3). When sensing a heavy uphill drive condition a target gear is determined for said uphill drive condition, said target gear being the highest possible gear with lowest possible gear ratio where the vehicle, in view of at least current circumstances, will be at least theoretically able to hold a constant vehicle speed or accelerate at least slightly, and where further selection of downshifts will be adapted so that no lower gear than said target gear will be selected and engaged.